821953 has 6 divisors (see below), whose sum is σ = 903602. Its totient is φ = 747120.

The previous prime is 821941. The next prime is 821971. The reversal of 821953 is 359128.

It can be written as a sum of positive squares in only one way, i.e., 543169 + 278784 = 737^2 + 528^2 .

It is not a de Polignac number, because 821953 - 2⁹ = 821441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (821993) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3276 + ... + 3517.

2⁸²¹⁹⁵³ is an apocalyptic number.

It is an amenable number.

821953 is a deficient number, since it is larger than the sum of its proper divisors (81649).

821953 is a wasteful number, since it uses less digits than its factorization.

821953 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6815 (or 6804 counting only the distinct ones).

The product of its digits is 2160, while the sum is 28.

The square root of 821953 is about 906.6162363426. The cubic root of 821953 is about 93.6732658029.

The spelling of 821953 in words is "eight hundred twenty-one thousand, nine hundred fifty-three".